Ocean Bottom Systems
Ocean bottom systems are crucial in expanding our understanding of coastal and deep-sea seismic processes. To monitor these previously unobtainable seismic movements we offer two types of ocean bottom solutions, temporary or permanent. Both these solutions are capable of monitoring at depths of up to 6km below sea level in the most hostile of environments on the planet. The challenges posed by the harsh ocean bottom conditions are colossal but through our leading designs and experience our solutions are truly world class.
Portable Freefall OBS
- Rigid HDPE cradles containing glass spheres and the sensor. The spheres contain the batteries, a digitiser, storage media and other electronics.
- Sacrificial concrete weights jetisoned on receipt of an acoustic signal when the sensor is to be recovered.
- Acoustic transponder system is used to obtain an accurate location for the sensor when deployed.
- GPS receiver, AIS radio broadcast and strobe aid location for recovery
- Can be supplied with a range of sensors, including the CMG-6TC OBS, a true triaxial, broadband, force-feedback seismometer mounted on dual, gravity-driven, microprocessor-controlled, electrically-braked gimbals. Other transducers, such as pressure gauges and hydrophones can be incorporated.
- Rugged sensors in direct contact with ocean bottom.
- Concrete dome to push sensor into mud on ocean floor and protect against: noise due to current, fluctuations, fish trawlers
- Optical fibre connection to single ground station, cable lengths in excess of 60km
- Pressure tested to 6000m depth
- Cheaper and easier to install because no ROV
- Options for single node and multinode connections
- No wet mating techniques necessary
- Real time monitoring
- Additional optional sensors: hydrophone, differential pressure gauge, acoustic doppler profiler, thermometer, magnetometer for orientation, tiltmeter
Selection criteria for ocean bottom systems
Ocean bottom systems should be chosen based on the scientific requirement. This is determined by the bandwidth, sensitivity and noise level required for that unit.